What does 'mandatory bolt-on' mean?

Mandatory bolt-ons are essential services for your new phone, such as unlimited internet or email, which are added on to the base cost of your tariff and included in your monthly bill. They help you to make the most of your phone's great features.

If you're looking to upgrade your Pay as you go phone, you can upgrade through our website. We have a quick and easy Pay as you go upgrade checker that will tell you whether or not you're eligible for upgrades online. Don't worry if you can't upgrade online, you can still go in store to check.

Here's how our upgrade checker works. Just type in your phone number and we'll send you a Pay as you go upgrade code via SMS in seconds. Type in your code, pop out your SIM card and enter the SIM serial number , select the network you are currently on, and you'll get the results straight away.

SIM Type

Nano SIM

Currently only iPhone 5 and iPad Mini use a nano SIM.

SIM Type

Micro SIM

Micro SIMs are found in modern phones, normally in smartphones such as the HTC One, Sony Xperia Z or Samsung Galaxy S4, but are also becoming more common in lower end smartphones.

Combi SIM

These can be used in the phones that use standard SIMs and micro SIMs. Keep the adaptor on for a larger SIM for phones like the Nokia Asha, or take the adaptor off for a smaller SIM for use in modern smartphones like the Samsung Galaxy S4.

SIM Type

Standard SIM

Standard SIMs are most popular in lower end phones such as the Samsung Galaxy Ace, Nokia Asha phones and older BlackBerry phones.

Combi SIM

These can be used in the phones that use standard SIMs and micro SIMs. Keep the adaptor on for a larger SIM for phones like the Nokia Asha, or take the adaptor off for a smaller SIM for use in modern smartphones like the Samsung Galaxy S4.